Long-term effect of anticancer therapy on dentition of Italian children in remission from malignant disease: A cross-sectional study.

AIM: To investigate the effects of anticancer therapy on dental development and caries formation in Italian childhood cancer survivors compared to healthy controls. METHODS: A total of 52 children treated with chemotherapy and/or radiotherapy when younger than 10 years and in remission from at least 2 years, and 52 healthy age- and gender-matched children were consecutively enrolled in this cross-sectional study. All participants were examined for dental caries and enamel defects according to the decayed-missing-filled teeth (dmft/DMFT) index and the Aine rating scale. Panoramic radiographs were taken to estimate dental age and to assess dental abnormalities using the Höltta Defect Index. CONCLUSION: These children are at high risk for tooth developmental abnormalities and poor dental health and should be closely monitored by a specialist dentist.

Comparative analysis of Laser and LED phototherapies pain control after insertion of elastomeric separators in orthodontics patients: Clinical trial.

The aim of this study was to evaluate the effectiveness of pain modulation following Laser or LED phototherapies during the process of tooth separation. This was a longitudinal randomized controlled clinical trial in four observational times carried out in 60 patients (15 males, 45 females, average 24.1 years old) who were randomly divided into three groups: G1 (LED, AsGaAl, λ850 ± 10 nm, 150 mW, 17 J/cm2, 57 s per session), G2 (Laser, AsGaAl, λ780 nm, 70 mW, 20.0 J/cm2, 240 s per session) and G3 (Non-irradiated Control). All patients were submitted to tooth separation using elastomeric separators. The pain level was measured by using a visual analogue scale (VAS) immediately after insertion (T1) of the elastic, at 48 (T2), 96 (T3) hours and 6 days (T4). It was observed an increase of the pain on the Control group from T1 to T2, with statistical significance. Pain levels in the LED and Laser groups were always significantly lower (<0.001), except for T1. According with the results of the present study it may be concluded that, either LED or Laser phototherapies, were effective in reducing the pain level after dental separation process when compared to the control group.

Is laser conditioning a valid alternative to conventional etching for aesthetic brackets?

AIM: ER:Yag lasers have been described as a more conservative alternative to conventional acid-etching enamel conditioning technique, when bonding conventional metallic orthodontic brackets. Since the use of aesthetic orthodontic brackets is constantly increasing, the purpose of the present report has been to test laser conditioning with different aesthetic brackets. MATERIALS AND METHODS: Study Design: Five different aesthetic brackets (microfilled copolymer, glass fiber, sapphire, polyoxymethylene and sintered ceramic) were tested for shear bond strength and Adhesive Remnant Index scores using two different enamel conditioning techniques (acid etching and ER:Yag laser application). Two hundred bovine incisors were extracted, cleaned and embedded in resin. Specimens were then divided into 10 groups with random tables. Half of the specimens were conditioned with conventional orthophosphoric acid gel, the other half with ER:Yag laser. Different aesthetic brackets (microfilled copolymer, glass fiber, sapphire, polyoxymethylene and sintered ceramic) were then bonded to the teeth. Subsequently all groups were tested in shear mode with a Universal Testing Machine. Shear bond strength values and adhesive remnant index scores were recorded. Statistical analysis was performed. RESULTS: When considering conventional acid etching technique, sapphire, polyoxymethylene and sintered ceramic brackets exhibited the highest SBS values. Lowest values were reported for microfilled copolymer and glass fiber appliances. A significant decrease in SBS values after laser conditioning was reported for sapphire, polyoxymethylene and sintered ceramic brackets, whereas no significant difference was reported for microfilled copolymer and glass fiber brackets. Significant differences in ARI scores were also reported. CONCLUSIONS: Laser etching can significantly reduce bonding efficacy of sapphire, polyoxymethylene and sintered ceramic brackets.

Diode laser irradiation and fluoride uptake in human teeth.

AIM: To evaluate chemically the effects of diode laser on fluoride uptake before and after laser irradiation of enamel surfaces. METHODS: Crowns of 20 sound human teeth were halved and a 3 x 3 mm acid-resistant varnish uncovered window left for: A) no treatment; B) fluoride (Elmex gel); C) diode (fluoride + diode laser); D) diode (diode laser + fluoride). The dental surfaces were analysed using a fluoride ion-selective electrode, in order to evaluate the fluoride treatment in combination with a diode laser. Also, to investigate laser-induced compositional changes (contents in F(-)) in enamel before/after laser irradiation and topical fluoride application. RESULTS: The mean ± SD of fluoride uptake of teeth of group A was 1.55 ± 0.89 mg/l. Mean fluoride uptake increased sevenfold after fluoride gel treatment: 10.51 ± 3.38 mg/l for group B, up to 15 times after gel and laser treatment: 23.62 ± 3.58 mg/l for group C and was 22.7 ± 4.60 mg/l for group D (diode laser before fluoride application). The Kruskal Wallis test indicated a statistically significant effect of fluoride uptake for all three treatments (p<0.001). The Student-Newman-Keuls multiple comparison test indicated a statistically significant increase of fluoride uptake before and after all treatments, and also a statistically significant difference for laser treatment versus fluoride gel. However, there was no statistically significance difference between laser groups. CONCLUSIONS: There is an enhanced capability of lasers to increase fluoride uptake of enamel and providing protection to enamel surface from acid attack.

FEM analysis of different dental root canal-post systems in young permanent teeth.

AIM: Aim of this work was to carry out a comparative evaluation of the structural behaviour of different root canal posts (cylindrical, conical and triple conical) fitted in a second lower bicuspid and subjected to compression and bending test. MATERIALS AND METHODS: This study has been carried out by numerical method of structural analysis of finite elements (FEM, Finite Element Method). Different tridimensional models were obtained by CAT images of an extracted tooth, endodontically treated, filled with guttapercha and triple conical glass post. Images have been elaborated by a software for images (Mimics and Ansys) and CAD (Rhinoceros 3 D). In the models a II Class restoration has been virtually created. In the numerical simulation dental tissues (enamel, dentine and root cement), guttapercha, root canal cement, different posts, different techniques of cementation and crown restoration (composites and adhesive systems) have been considered. RESULTS: Strain distributions in dental tissues, in root canal cement and in posts have been compared. The equivalent tensions and the single components (traction, compression and cut) have been analysed. In all examined posts, the most strained part is resulted the coronal one, even if the total tension, in the different tooth-post analyzed systems, resulted uniformly distributed. A similar behaviour was shown by the root canal cement. CONCLUSIONS: According to the analyzed conditions of bond and load, varying according to the geometry of the considered posts, our results confirm that there is no substantial difference of deformation in posts, root canal cement and treated tooth.